From c53e5c0c191ec6cc85c630249cbd68a2adb3f715 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Wed, 30 Apr 2025 23:10:44 -0400 Subject: [PATCH] docs: bcachefs: add casefolding reference Signed-off-by: Kent Overstreet --- .../filesystems/bcachefs/casefolding.rst | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/Documentation/filesystems/bcachefs/casefolding.rst b/Documentation/filesystems/bcachefs/casefolding.rst index ba5de97d155f..871a38f557e8 100644 --- a/Documentation/filesystems/bcachefs/casefolding.rst +++ b/Documentation/filesystems/bcachefs/casefolding.rst @@ -88,3 +88,21 @@ This would fail if negative dentry's were cached. This is slightly suboptimal, but could be fixed in future with some vfs work. + +References +---------- + +(from Peter Anvin, on the list) + +It is worth noting that Microsoft has basically declared their +"recommended" case folding (upcase) table to be permanently frozen (for +new filesystem instances in the case where they use an on-disk +translation table created at format time.) As far as I know they have +never supported anything other than 1:1 conversion of BMP code points, +nor normalization. + +The exFAT specification enumerates the full recommended upcase table, +although in a somewhat annoying format (basically a hex dump of +compressed data): + +https://learn.microsoft.com/en-us/windows/win32/fileio/exfat-specification -- 2.50.1